Overall an enjoyable unit, since I've done aerodynamics I and II I don't think my comment on the difficulty of this unit will be accurate. With that said I'd give this unit a 7/10 in difficulty. This unit is separated into two sections, compressible and incompressible flow. The first section was quite easy, it's mostly algebra manipulation and some vector calculus stuff. For people who has done aerodynamics, the only thing that's new would be tensor calculus, which is not overly difficult but can get quite confusing the first few times you play with it. Once you find the trick it becomes free mark in exam. I can't comment too much on the lecture since I haven't been but the lecture notes were top notch. The typed notes were short, concise and to top it off, the hand written worked examples were actually readable! There will be a revision test on week 2 for vector calculus (not too difficult, just have to memorise Stoke's theorem) and a mid semester test later on, which is also not too bad if you went through the tutorial solutions.
The second part was almost entirely application, you'll actually learn some interesting flow but the amount of estimation here was on a similar level to astrophysics units (which has been bugging me to no end). This section involves dynamic similarity, similarity equation, exact solution to 1 dimensional flow, perturbation, stokes flow, Reynolds number and a slight touch on boundary layer. If you think this is a lot of content, well that's because it is, you'll have enough time to learn all these but it might be better to rote learn some of them. The assignment was really challenging, frustrating but personally I really enjoyed it. The exam will take the whole 3 hours to complete and part II will give you a lot of headache, just a heads up.